Method of recovering zinc compounds and ammonia.



E. G. & M. M. PBARLMAN.

METHOD OF REGOVERING ZINC COMPOUNDS AND AMMONIA.

APPLIUATION FILED 0613,1908.

Patented Apr. 2'2, 1909.

u MILIHJ HI IIIIII Ill! 1 WITIYESSES ATTORNEY.

sulfate of ammonia, substantia with a stack a, which is closed at t 'umrnn srAirEs PATENT OFFICE.

ELIAS G. PEARLMAN AND MARTIN M. PEARLMAN, OF PHILADELPHIA, PENNSYLVANIA.

IMETHOD OF RECOVERING ZTNC COMPOUNDS AND AMMONIA.

Specification of Letters Patent.

Patented April 27, 1909.

Application flied October 8, 1908. Serial No. 455,948.

To altwhom it may concern:

Be it known that we, ELIAS G. PEARLMAN and MARTIN M. PEARLMAN, both citizens of the United States, residing in the city of Philadelphia, in the county of Philadelphia and State of-Pennsylvania, have jointly invented certain new and useful Improvements in the Method of Recover-in Zinc Compounds and Ammonia, of which t iefollowing is a specification.

Our invention relates to a method of treating ammonia gas and zinc chlorid fumes resulting from roasting or smelting sal-ammoniac fluxes or skimmings, by-products of the galvanizing process," to recover zinc compounds and ammonia and to convert'the same into commercial products, as zinc hydrate or oxy-hydrate, and into an ammonia byroduct, as sulfate of ammonia. The said noxious ammonia gas and pungent zinc chlorid fumes arising from treatments of the described fluxes or skimmings, exist in varying pro ortions, and in the past have been given 0 to the atmosphere in the roasting or smelting of the same.

The principal object of our said invention is to utilize the said gas andfumes, under certain treatments, in different solutions, to produce commercial products as zinc hydrate or wry-hydrate and sulfate of ammonia,-or other similar products, according to the character or composition of the solutions employed, for mixing or combining such gas and fumes therewith, for deriving resultant commercial products therefrom.

' Our said invention. therefore, stated in general terms, consists of recovering zinc compounds and ammonia, as commercial ucts, in thel'orm of zinc hydrate or oxyby-product, as

ly in the manner hereinafter described and claimed.

The nature and scope of our invention will be more fully understood from the following description taken in connection with the acoompan ing drawing, illustrating diagrammatlcal y a plant found economical and eflicient for carrying into effect therein our-said method.

Referring to the drawing :A, is an ordinary roasting or smelting furnace, in which is adapted to be introduced a batch of sal-ammoniac fluxes or skimmings, by-products of the galvanizingl process, in the manufacture of spelter. T c said furnace is rovided e top 1)..

Tot hydrate and an ammonia In the side of the stack is provided an opening, in which is introduced aterra-cotta or other suitable conduit 0. This conduit may be cxtcriorly covered with asbestos or other material to protect the same against Weather conditions. The forward end of the conduit 0, is closed and provided with-a )ipe (1, extending therefrom mto a chambered injector device 1;, preferably of the Schuttc- Korting type, for injecting in jet-like form, steam therethrough. A supply ipef, is arranged so as to be connected wit the device e, and is provided with a cut off valve f From the device e, extends downward a pipe 9, into a vertical closed vessel H, and from which vessel extends a pipe b into a similar vessel H.

In the vessels H and H respectively, if used in connected series, are placed solutions of quick lime or calcium hydrate, which are agitated by the steam introduced through the pi e it, along with the ammonia gas and zinc c lorid fumes from the conudit c, of the roasting 0r smelting furnace A, conveyed thereinto and by such combined actions upon the said gas and fumes in each of the vessels H and H, is roducedvolatilized chlorid of zinc and V0 atilized ammonium chlorid or sal-ammoniac, due to the saturated solution of calcium-hydrate or quick solutions of the vessels H and H Through the chlorid of zinc reacting with the calcium hydrate therein, is produced the following reaction:

zno1,+ choir), Zn on 021.01,.

The zinc hydrate formed being a solid remains in the vessel H or H, or both connected vessels, w1th the excess of. uicka solid, remains therein, but in a deliquescent state.

Through the sal-ammoniac or ammonium chlorid, reacting with the calcium-hydrate in the vessel H or H, or both connected vessels, occurs the following reaction:

lime therewith, in each of the said agitated lime. The calcium chlorid also formed eing pipe 11 through w calcium-hydrate. The action in the second vessel H serves merely. as a safeguard against any incomplete reactions in the first vessel H, and thus preventing waste of a valuable product to be utilized under condi tions as above defined. The ammonia gas as above then passes on through a pipe H into a tank I, partly open at '5, and having a depending roof or dome i, extending down into a suitable solution of this tank, preferably, consisting of dilute sulfuric acid, for converting readily the ammonia gas of the solution into sufate of ammonia, as a com-- mercial roduct. Such reaction taking place The ammonium sulfate thus formed is a solid and the other product is water. of the foregoin commercial products thus obtained being erived in the described manner from the makin scribed, it will be found as extended practice has demonstrated, that the ammonia gas and chlorid fumes arising from the treatment of the; principalmaterial are notonly fully recovered and utilized, but any vapors liber-' ated into the atmosphere, will be odorless and unobjectionable.

In the bottom of each operation thereof, permitting rate recovered r5;

' pounds and Both as a resultant product, zinc by rate. or oxyoi the vessels H and .H*, are provided plug valves h, for by the the freeing of the zinc hydrate or oxy-hy into receptacles ht, for use.

We claim i 1. The method of recovering zinc comammonia, which consists in roasting or smelting sal-ammoniac-fiuxes or skimmings, by-products offthe galvanizing rocess, acting on the gases and fumes given off first with steam, then with an alkaline solution and finally treating the remaining gases with an acid solution, substantially as 5 and for the-purposes described.

2. The method of recovering'zinc compounds and ammonia, which consists in roasting or smelting sal-ammoniac fluxes or slriminings, by-products of thegalvanizing process, passing the gases and i'umesgivenv off with steam through 'analkaline solutkilon V drate or oxy-hydrate-andthen further actto derive. as a resultant product, zinc ing on the remaining'gases an acid solution, to derive as a resultant product, an ammonium salt, substantially as described.

3. The methodroasting or @ieltingsal-arhmoniac fluxes or skimmings, by-pro dem 0f the galvanizing process, passing the gases and fumes given ofi through agitatedmilkof li eto .derive hydrate and then passing theremaining gases 75 through a solution of sulfuric. acid to derive asa resultant product,'sulfate of ammonia, substantially as described. Q

In Witness I hereof, we have hereunto'set our signatures in'the presenoe bf two'sub- C scribing witnesses. v .7 ELIAS G. PEARLMAN.

MARTIN M. PEARLMAN.

:' Witnesses: 1

J. WALTER DOUGLASS, THOMAS M..SMITH.

of recovering zinc com-' f pounds and ammon a; v.whwh consists in I 

